On Tue, Apr 02, 2024 at 01:37:50PM +0300, Dan Carpenter wrote:
> On Mon, Apr 01, 2024 at 09:22:52PM +0200, Alexander Wetzel wrote:
> >
> > > Following kernel warnings have been noticed on qemu-x86_64 while running LTP
> > > cve ioctl_sg01 tests the kernel with stable-rc 6.6.24-rc1, 6.7.12-rc1 and
> > > 6.8.3-rc1.
> > >
> > > We have started bi-secting this issue.
> > > Always reproduced.
> > >
> > > Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> > >
> > > ioctl_sg01.c:81: TINFO: Found SCSI device /dev/sg0
> > > ------------[ cut here ]------------
> > > [ 36.606841] WARNING: CPU: 0 PID: 8 at drivers/scsi/sg.c:2237
> > > sg_remove_sfp_usercontext+0x145/0x150
> > > [ 36.609445] Modules linked in:
> > > [ 36.610793] CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.6.24-rc1 #1
> > > [ 36.611568] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
> > > BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
> > > [ 36.612872] Workqueue: events sg_remove_sfp_usercontext
> > > [ 36.613691] RIP: 0010:sg_remove_sfp_usercontext+0x145/0x150
> > >
> > > <trim>
> > >
> > > [ 36.621539] Call Trace:
> > > [ 36.621953] <TASK>
> > > [ 36.622444] ? show_regs+0x69/0x80
> > > [ 36.622819] ? __warn+0x8d/0x150
> > > [ 36.623078] ? sg_remove_sfp_usercontext+0x145/0x150
> > > [ 36.623558] ? report_bug+0x171/0x1a0
> > > [ 36.623881] ? handle_bug+0x42/0x80
> > > [ 36.624070] ? exc_invalid_op+0x1c/0x70
> > > [ 36.624491] ? asm_exc_invalid_op+0x1f/0x30
> > > [ 36.624897] ? sg_remove_sfp_usercontext+0x145/0x150
> > > [ 36.625408] process_one_work+0x141/0x300
> > > [ 36.625769] worker_thread+0x2f6/0x430
> > > [ 36.626073] ? __pfx_worker_thread+0x10/0x10
> > > [ 36.626529] kthread+0x105/0x140
> > > [ 36.626778] ? __pfx_kthread+0x10/0x10
> > > [ 36.627059] ret_from_fork+0x41/0x60
> > > [ 36.627441] ? __pfx_kthread+0x10/0x10
> > > [ 36.627735] ret_from_fork_asm+0x1b/0x30
> > > [ 36.628293] </TASK>
> > > [ 36.628604] ---[ end trace 0000000000000000 ]---
> > > ioctl_sg01.c:122: TPASS: Output buffer is empty, no data leaked
> > >
> > > Suspecting commit:
> > > -----
> > > scsi: sg: Avoid sg device teardown race
> > > commit 27f58c04a8f438078583041468ec60597841284d upstream.
> > >
> >
> > Correct. The issue is already been worked on.
> >
> > commit 27f58c04a8f4 ("scsi: sg: Avoid sg device teardown race") fixed a real
> > issue. But also added an incorrect WARN_ON_ONCE(). Thus the scary - but
> > otherwise harmless - error message.
>
> If you have Reboot on Oops turned on (apparently Android enables this)
> then WARN() will reboot the system so it can be pretty annoying.
Agreed, I've dropped this stable change for now because of this.
greg k-h
